1. Field of the Invention
The present invention relates to a motor.
2. Description of the Related Art
A conventional motor is disclosed in, e.g., Japanese Patent Application Publication No. 2004-229468. The motor disclosed in this publication includes a center piece provided as a support member and a stator core fixed to the center piece (see Paragraph 0020 and FIGS. 1 and 3 of JP 2004-229468. In this motor, a bearing is press-fitted and fixed to the inner circumferential surface of a cylindrical portion of the center piece (see Paragraph 0022 and FIG. 1 of JP 2004-229468).
JP 2004-229468 also discloses an example in which a plurality of projections is formed on the outer circumferential surface of the cylindrical portion of the center piece (see Paragraph 0043 and FIG. 5 of JP 2004-229468). In this example, a plurality of salient portions formed in the stator core makes pressure contact with the outer circumferential surface of the center piece existing between the projections, whereby the center piece and the stator core are fixed to each other.
In the structure in which the center piece and the stator core are brought into pressure contact with each other, however, it is sometimes the case that the center piece is deformed radially inward. If the center piece undergoes radially inward deformation, it is likely that a small distortion is generated a bearing fixed to the inner circumferential surface of the center piece. The small distortion of the bearing may be permitted depending on the use of a motor. However, with a view towards obtaining a higher quality motor, there is a strong demand to reduce the distortion of the bearing.